The present invention relates to a vacuum cleaner, specifically to a telescopic dust-collecting pipe for vacuum cleaner.
The known technology, such as EP0293518, has disclosed a dust collecting pipe of vacuum cleaner, including inner pipe, outer pipe and locking device. While pushing the button of said locking device in one direction, locking device could be released, and the inner and the outer pipe could be relatively extended or contracted. However, the button could be pushed only in one direction to release the locking device, while extending and contracting dust-collecting pipe, the directions of the force applied on the dust-collecting pipe are two opposite directions. Therefore, the directions of force applied on the button and on the dust-collecting pipe with same hand are just opposite and it is inconvenient for operating.
To overcome disadvantages of above known technology, the present inventor has proposed a Chinese patent application 00216141.9 titled xe2x80x9cTelescopic Dust-Collecting Pipe for Vacuum Cleanerxe2x80x9d. Its locking device includes a hollow outer layer oriented rack provided on the outer surface of the inner pipe axially and a controlling rod slid relatively to the inner cavity of the hollow outer layer oriented rack as locking oriented mechanism. And on the hollow outer layer oriented rack and the top face of the controlling rod are provided with oriented concave grooves correspondingly. Controlling rod can connect with operating device. Locking block provided in the locking device is pressed against one side of the inner pipe by an elastic element. The working principle of the patent is that in the locking condition, under the pressing of the elastic element the locking block enters into the oriented concave grooves coincided each other of hollow outer layer oriented rack and controlling rod. When extending or contracting telescopic pipe is required, pushing or pulling operating device, controlling rod can produce two directions axial movement relatively to the hollow outer layer oriented rack, and then produces displacement relatively to the hollow outer layer oriented rack. In the meantime locking block is pushed out of the oriented groove and is in releasing condition. As such, the user of the vacuum cleaner can complete the operation of extending or contracting of the extendible and contractible pipe by using push action or pull action of only one hand. The disadvantage of inconvenient operation can be solved substantially.
However, in extending and contracting of this kind of dust collecting pipe and the oriented mechanism of its locking device, outer layer oriented groove on hollow outer layer oriented rack made of metal material has an upward opening end. And the upward opening end is on the surface of telescopic pipe. Therefore, surface processing has to be done for it. Electroplating is normal method. Since it is more difficult to process the side wall of the opening end during surface processing such as electroplating and so on. Therefore, not only increases production cost but also it is difficult to insure its production quality. On the other hand, the opening end of the outer layer oriented groove is on the surface of the telescopic pipe. During long time using, at the opening end dust is easy to enter and difficult to clean. After dust is entering, relative movement between hollow outer layer oriented rack at outside and controlling rod at inside will be not smooth so as to affect its freedom of extending and contracting. In addition, in order to reduce the production difficulty of integral forming of locking device, the hollow outer layer oriented rack provided axially along outer wall of the inner pipe and the inner pipe are separate elements. And planar connecting structure between rack and wall of inner pipe are adopted usually. In general, hollow outer layer oriented rack is welded on the outer wall of the inner pipe by using spot weld. So it is not avoidable that welding spot will appear on the surface of the hollow outer layer oriented rack and the integral appearance of telescopic pipe will be distorted. In addition, the stability of this planar connecting structure is not good enough and easy to break off welded.
To overcome disadvantages of above known technology, the object of the invention is to provide a telescopic dust collecting pipe for vacuum cleaner so as to improve the process technology of locking device on the basis of convenient operating by improving connecting structure in the locking device. And causing it simple structure, easy to produce, and insuring stability of the connecting structure of its components. And revealing opening end of the oriented groove is avoidable so as to cause the body of the telescopic pipe not only has tidy appearance, difficult to accumulate dust, but also insuring its quality for using.
The object of the invention is achieved such that a telescopic dust collecting pipe for vacuum cleaner including outer pipe, inner pipe provided slidingly in outer pipe. The outer pipe is connected with the inner pipe by locking device. The locking device comprises of locking oriented mechanism and locking element. Its characteristic is in that, oriented mechanism includes fixed element fixed relatively to the inner pipe and moving element producing axial movement relatively to the fixed element. Oriented groove is arranged axially at least on the same side faces of the fixed element and moving element to form inner, outer double layer oriented groove structures. Moving element connects with operating device and moves axially due to the driving of the operating device, to coincide or stagger inner layer oriented groove with outer layer oriented groove. Said locking element is pressed from side against the direction of the oriented groove by a elastic element. While inner layer oriented groove coincides with outer layer oriented groove locking element can enter into the oriented grooves coincided and locking inner pipe and outer pipe relatively. While inner layer oriented groove staggers with outer layer oriented groove due to axial movement of moving element, locking element is pushed out by groove wall of the inner layer oriented groove and locking condition between inner pipe and outer pipe is released.
Oriented groove arranged axially could be arranged along two side faces of fixed and moving elements. Locking element is pressed against the above oriented groove from two side faces showing pincer-like by elastic element.
Fixed element could be hollow and outer layer oriented groove could be provided on it. Said moving element is provided slidingly in the hollow of the fixed element and inner layer oriented groove is provided on it. The inner layer oriented groove slopes inward from two side faces axially.
Moving element could be also hollow and outer layer oriented groove is provided on it. Said fixed element is provided in the hollow of the moving element and inner layer oriented groove is provided on it. The inner layer oriented groove slopes inward from two side walls axially. One end of the moving element is connected with operating device firmly. The operating device sheaths slidingly on the outside of inner pipe. At least one end of moving element provides with an elastic axial recovering element.
Fixed element could be in hollow shape and it may be hollow outer layer oriented rack. The hollow outer layer oriented rack is provided protrudingly on the outer wall of the inner pipe. Said moving element is arranged in the hollow outer layer oriented rack. An axial opening is provided along top end of hollow outer layer oriented rack. Moving element formed by a controlling rod is provided slidingly in the outer layer oriented rack. The top end of the controlling rod is provided with a flange covering axial opening of top end of hollow outer layer oriented rack. The lower end of hollow outer layer oriented rack could be inlaid in the outer wall of inner pipe.
It is priority that locking element could be locking block or roller. The locking elements could be arranged on two side faces which are corresponding to the oriented grooves and be pressed against one side of the oriented groove by elastic element respectively.
Elastic axial recovering element could be provided on one end of moving element. One end of the elastic element is fixed on one end of inner pipe and the other end is fixed on moving element.
Elastic axial recovering element could be also provided on two axial ends of moving element.
Two ends of moving element could be provided with axial limiting device to limit maximum stroke of moving element.
Locking element is inlaid in controlling pedestal and the controlling pedestal could be provided slidingly along outer wall of the inner pipe.
The basic structure of the invention adopts a fixed element and a moving element as locking oriented mechanism. And on the fixed and moving elements the oriented grooves corresponded each other and arranged axially form inner and outer double layer oriented groove structures to control axial movement of moving element so as to coincide or stagger inner layer oriented groove with outer layer oriented groove. While locking block enters into inner, outer layer oriented grooves coincided, the telescopic pipe is locked. While inner, outer layer oriented grooves are staggered, locking block will be pushed out of the oriented grooves, the telescopic pipe is released. Such that the pushing or pulling operation of controlling rod could achieve extending or contracting of telescopic pipe so as to cause the invention has the characteristic of convenient operating. While the most important characteristic of the invention is that the opening end of oriented groove in the locking device is provided on the side faces of the moving element and fixed element fitted with it. Locking block is pressed into the oriented grooves from side face by an elastic element. So that the upper surface of fixed element may not have opening end again and causing the outer surface of telescopic pipe has tidy appearance as well as prevent opening end from entering dust. Likewise, may also cause processing accuracy of its outer surface reducing greatly and simple processing method could be adopted. Therefore, its producing cost will be reduced greatly.
In the preferable embodiment of the invention, opening grooves of the locking oriented mechanism are arranged symmetrically on two side surfaces of both fixed and moving elements and showing pincer-like locking condition. The stability of the structure is better as well as the condition subjected force of pushing or pulling and can cause extending and contracting operation of telescopic pipe more smoothly. In addition, the fixed element in oriented mechanism may be designed in open style. Manufacturing is simpler and easier to assemble.